The 2-inch-long camera was lowered into a vault inside a pyramid at the Palenque archaeological site, in the hills of the southern Mexican state of Chiapas. Archaeologists have known about the vault since 1999, but the only access to the room was through a small shaft in the pyramid — just big enough to fit the micro-camera through.

The images reveal a series of nine figures painted on the walls in black on a vivid, blood-red background. Dishes, apparently meant to hold funerary offerings, are set on the floor. The camera also spotted pieces of a funerary shroud made of jade and mother of pearl. "The characteristics of the funeral site show that the bones could belong to a sacred ruler from Palenque, probably one of the founders of a dynasty," Reuters quoted archaeologist Martha Cuevas as saying.